The linear actuators are extensively used in daily life. Devices/products utilize the linear actuators includes, for example, a massage chair, an electrically adjustable chair, an electric hospital bed, a treadmill, a foldable bed, furniture, and a lift mechanism. The linear actuator is typically used for position adjustment. A conventional linear actuator mainly utilizes a drive assembly including a drive motor, a worm, and a worm gear, so as to drive rotation of a lead screw. At the same time, by means of the lead screw, an extendable pipe threadedly fastened to the lead screw extends or retracts with respect to an outer pipe receiving the extendable pipe.
The conventional linear actuator includes many parts inside. If it also has a gearbox (a deceleration gear assembly), assembling will take more time and often have more problems. In other words, assembling is time-consuming and costly. On the other hand, in small-size electronic products, the linear actuator has to be miniaturized to save space and reduce costs.
Accordingly, it is the aim of the present invention to solve the above-mentioned problems, on the basis of which the present invention is accomplished.